Instead, far out to sea in a tiny 20-foot research boat, Calambokidis and a colleague were seeing something so extraordinary it had been documented off Washington’s coast only twice before in the past 50 years — a blue whale, the largest animal on Earth.

Over the course of the afternoon last Thursday, he would snap 100 photographs and watch as six of the glistening light-blue cetaceans glided beneath the surface in pairs and dived repeatedly above a deep underwater feature known as Guide Canyon.

Calambokidis, one of the world’s foremost experts on the blue whale, has seen these massive marine mammals in California and South America so often that his organization, Cascadia Research, can actually identify individual animals by their markings. And yet spying so many of them up close in a place so unexpected was, for him, a spectacular experience.

“It’s still an incredible thrill,” Calambokidis said. “Here’s the biggest animal that ever lived, and it’s this beautiful, shimmering color. I get excited every time I see one.”

The moment reminded him of a quote from Seattle whale biologist Dale Rice, who once wrote, “There is no whaler and no whale biologist, no matter how experienced, who is so jaded that his heart does not race at the sight of a blue whale.”

At 150 tons, an adult blue whale is heavier than the biggest dinosaurs were, and can reach a length of 100 feet. Its two-ton heart can weigh as much as a great white shark, with valves large enough for a child to crawl through. They burn 3 million calories a day.

“The thing that’s the most awesome about blue whales is that when you see one blow at the surface it goes 30 feet in the air and just hangs there in this column of mist,” said Steve Jeffries, a marine-mammal biologist with the Washington Department of Fish and Wildlife. “With gray whales and humpbacks it’s over in two or three seconds. With blue whales it seems to hang in the air forever.”

With perhaps 10,000 left on Earth and maybe 2,000 found in the eastern North Pacific, blue-whale numbers are 10 percent of what they likely were in the 1800s, before decades of worldwide whaling. It’s difficult to know whether sightings off the Northwest coast are rare because their presence here is unusual, or because the endangered whales visit in winter when the weather and water are so rough no one is out there to see them.

But Jeffries and Calambokidis both said that the sighting helps confirm something whale researchers across the globe are only just beginning to understand: Blue whales, unlike other krill-eating baleen whales such as grays and humpbacks, don’t fast in winter and head to warmer breeding grounds. They keep eating and are probably dispersed. The creatures were there because the steep canyon creates upwelling that brings krill and phytoplankton up from the deep.

“What it reveals, I think, is that there isn’t any one single calving or breeding ground that they all go to,” Calambokidis said. “They’re extremely mobile and shift their feeding from location to location.”

Last week’s sighting was part of a joint three-year research project between Washington, Oregon and Cascadia Research. During a rare seven-day clear spell, the state biologists in a 56-foot research boat surveyed for whales far off the coast from Neah Bay to Newport, Ore. When they spied a large contingent, they’d contact Calambokidis, who would rush out to the area to take a more detailed look.

Last Thursday, Calambokidis, who had an official research permit, headed out with a colleague to photograph and attach satellite-tracking devices on humpbacks seen earlier by the state boat.

Not long after, they spied the massive release from a whale’s blow hole off in the distance.

Calambokidis brought his boat to within 50 feet of the blue whales, while biologist Greg Schorr attempted to attach a tracking device, but the water proved too rough. But the researchers have high hopes for next year — even Jeffries, who wasn’t with Calambokidis that day.